Is it necessary to have more then the winxp SP1 firewall?

[Zee]

was having a discussion with someone, and basically on a clean, maintained computer, is Internet Connection Firewall (ICF) is more then sufficient? My friend says that ICF is garbage.

On that note, my friend showed me that when he runs bittorent, bittorent connects with other clients on ports that have not been openned in ICF.

I tried it on my computer and found that he is correct. Ports I have not openned are used to connect to other computers when using bittorent. Does that prove that ICF is garbage?

 

[Mo0o]

On my school's network i run a 3rd party firewall plus norton system works, im always virus free. I've had to help reformat 3 of my friends computers because they didn't think a firewall was necessary.